Publications by authors named "Chu Pek Lim"

Radiotherapy is an integral modality in treating human cancers, but radioresistance remains a clinical challenge due to the involvement of multiple intrinsic cellular and extrinsic tumour microenvironment factors that govern radiosensitivity. To study the intrinsic factors that are associated with cancer radioresistance, we established 4 radioresistant prostate (22Rv1 and DU145) and head and neck cancer (FaDu and HK1) models by irradiating their wild-type parentals to 90 Gy, mimicking the fractionated radiotherapy schema that is often using in the clinic, and performed whole exome and transcriptome sequencing of the radioresistant and wild-type models. Comparative genomic analyses detected the enrichment of mismatch repair mutational signatures (SBS6, 14, 15, 20) across all the cell lines and several non-synonymous single nucleotide variants involved in pro-survival pathways.

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Unlabelled: Prostate cancer is frequently treated with radiotherapy. Unfortunately, aggressive radioresistant relapses can arise, and the molecular underpinnings of radioresistance are unknown. Modern clinical radiotherapy is evolving to deliver higher doses of radiation in fewer fractions (hypofractionation).

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Cholangiocarcinomas (CCA) pose a complex challenge in oncology due to diverse etiologies, necessitating tailored therapeutic approaches. This review discusses the risk factors, molecular pathology, and current therapeutic options for CCA and explores the emerging strategies encompassing targeted therapies, immunotherapy, novel compounds from natural sources, and modulation of gut microbiota. CCA are driven by an intricate landscape of genetic mutations, epigenetic dysregulation, and post-transcriptional modification, which differs based on geography (e.

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Objectives: Cholangiocarcinoma (CCA) is a heterogeneous malignancy with high mortality and dismal prognosis, and an urgent clinical need for new therapies. Knowledge of the CCA epigenome is largely limited to aberrant DNA methylation. Dysregulation of enhancer activities has been identified to affect carcinogenesis and leveraged for new therapies but is uninvestigated in CCA.

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PBRM1 encodes an accessory subunit of the PBAF SWI/SNF chromatin remodeller, and the inactivation of PBRM1 is a frequent event in kidney cancer. However, the impact of PBRM1 loss on chromatin remodelling is not well examined. Here we show that, in VHL-deficient renal tumours, PBRM1 deficiency results in ectopic PBAF complexes that localize to de novo genomic loci, activating the pro-tumourigenic NF-κB pathway.

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There is an increasing number of radiobiological experiments being conducted with low energy protons (less than 5 MeV) for radiobiological studies due to availability of sub-millimetre focused beam. However, low energy proton has broad microdosimetric spectra which can introduce dosimetric uncertainty. In this work, we quantify the impact of this dosimetric uncertainties on the cell survival curve and how it affects the estimation of the alpha and beta parameters in the LQ formalism.

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Purpose: Improved antitumor responses have been observed in patients after combination radiation therapy (RT) and immune checkpoint blockade (ICB). Whether these clinical responses are linked to the host systemic immune system has not been elucidated.

Methods And Materials: In this single-institution prospective observational study, peripheral blood was longitudinally collected from 10 patients with metastatic disease who had responded to anti-PD-1/anti-PD-L1 ICB and received RT (8-50 Gy in 1-5 fractions) upon disease progression at the following timepoints: baseline (pre-RT), 1 to 2 weeks post-RT, and post-ICB (cycle 1) on reintroduction post-RT.

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Upconversion nanoparticles (UCNPs) are the preferred choice for deep-tissue photoactivation, owing to their unique capability of converting deep tissue-penetrating near-infrared light to UV/visible light for photoactivation. Programmed photoactivation of multiple molecules is critical for controlling many biological processes. However, syntheses of such UCNPs require epitaxial growth of multiple shells on the core nanocrystals and are highly complex/time-consuming.

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Background: Epidermal growth factor receptor (EGFR) overexpression is characteristic in head and neck cancers and is associated with tumour regrowth following photodynamic therapy (PDT).

Purpose: We investigated vandetanib, which selectively blocks EGFR and vascular endothelial growth factor receptor-2 (VEGFR-2), to enhance the efficacy of PDT.

Methods: We assessed the in vitro therapeutic efficacy of: 1) vandetanib; 2) PDT with the photosensitizer Chlorin e6 (Fotolon®); and 3) combined PDT + vadetanib treatment in CAL-27 oral squamous cell carcinoma (OSCC) cell line by cell viability, γH2AX foci immunostaining, cell cycle arrest and western blot.

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